1. Field of the Invention
The present invention relates to an optical film capable of preventing reflection of external light, and an organic light emitting display (OLED) apparatus including the same.
2. Description of the Related Art
In general, flat display devices may be classified into an emissive type and a non-emissive type. The emissive type includes a flat cathode ray tube, a plasma display panel (PDP), an electro luminescent device, a light emitting diode (LED), and the like. The non-emissive type includes a liquid crystal display (LCD) device. From among them, the electro luminescent device has a wide viewing angle, an excellent contrast and a fast response speed, and thus is regarded as a representative next-generation display device. Electro luminescent devices are classified into an inorganic electro luminescent device and an organic electro luminescent device according to a material for forming an emission layer (EML).
An organic electro luminescent device is a self light emitting display device for emitting light by electrically exciting a florescent organic compound, is capable of realizing low-voltage driving, a thin size, a wide viewing angle, a fast response speed and the like which are not enabled in an LCD device, and thus is regarded as a next-generation display device.
An organic electro luminescent device includes an EML formed of an organic material between an anode electrode and a cathode electrode. In the organic electro luminescent device, as plus and minus voltages are applied to the anode and cathode electrodes, holes injected from the anode electrode move to the EML via a hole transport layer (HTL), electrons move from the cathode electrode to the EML via an electron transport layer (ETL), and the electrons and the holes are recombined in the EML so as to generate exitons.
As the exitons change from an excited state to a ground state, fluorescent molecules in the EML emit light so as to form an image. A full color organic electro luminescent device realizes full colors by including pixels for emitting red (R), green (G) and blue (B) light.
In the organic electro luminescent device, a pixel define layer is formed at two ends of the anode electrode. Then, an opening is formed in the pixel define layer, and the EML and the cathode electrode are sequentially formed on the anode electrode exposed due to the opening.